Natural Resources Conservation Service

Ecological site R077CY022TX Deep Hardland 16-21" PZ

Accessed: 09/29/2021

General information Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

Figure 1. Mapped extent Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.

MLRA notes Major Land Resource Area (MLRA): 077C–Southern High Plains, Southern Part

MLRA 77C is characterized by nearly level plains with numerous playa depressions, moderately sloping breaks along drainageways, and a steep escarpment along the eastern margin. From southwest to northeast, soils grade from coarse-textured to fine-textured. Soils are generally deep and occur in a thermic soil temperature regime and ustic soil moisture regime bordering on aridic. Current land use is dominantly cropland.

Classification relationships This ecological site is correlated to soil components at the Major Land Resource Area (MLRA) level which is further described in USDA Ag Handbook 296

Ecological site concept This site occurs on very deep, gently sloping clay loam soils on uplands. Although the soils are deep and well drained, the nature of the clay soils can cause the site to be particularly sensitive to dry conditions. The reference vegetation consists of shortgrasses with some midgrasses and few forbs. Abusive grazing practices may lead to the suppression of palatable species and a shift in the community. Without periodic fire or alternative brush management, woody species may encroach on the site. Associated sites R077CY028TX Limy Upland 16-21" PZ Generally adjacent and upslope of the Deep Hardland site. The soils are loamy in texture and highly calcareous. Shortgrasses dominate, but has a good mixture of midgrasses on the site. More productive than the Deep Hardland site. R077CY037TX Very Shallow 16-21" PZ Generally associated with changes in slope, scattered areas may occur as rocky outcrops or small knolls and ledges. The soil is shallow, gravelly loams and highly calcareous. The plant community consist of sparse stands of midgrasses with some tallgrasses. The shallow nature of the soils limits production.

Similar sites R077EY055TX Hardland Slopes 16-24" PZ This site has deep to very deep clay to clay loam soils like the Deep Hardland site. Slopes will be sloping with a plant community dominated by shortgrasses. Production is less than Deep Hardland.

Table 1. Dominant plant species Tree Not specified Shrub Not specified Herbaceous (1) Bouteloua gracilis (2) Bouteloua dactyloides

Physiographic features This site occurs on the large nearly level to moderately sloping upland plateau formed in moderately alkaline windblown loess deposits of the Blackwater Draw Formation of Pleistocene age. A few ancient drainage ways dissect this plateau and relatively shallow closed depressions are scattered throughout the area. The elevation ranges from 2,800 feet to 4,500 feet above sea level. Slopes range from 0 to 5 percent. The site is extensively used for cultivated cropland, as well as rangeland.

Table 2. Representative physiographic features

Landforms (1) Plain Flooding frequency None Ponding frequency None

Elevation 2,800–4,500 ft

Slope 0–5%

Water table depth 60–80 in Aspect Aspect is not a significant factor

Climatic features Climate is semi-arid dry steppe. Summers are hot with winters being generally mild with numerous cold fronts that drop temperatures into the single digits for 24 to 48 hours. Temperature extremes are the rule rather than the exception. Humidity is generally low and evaporation high. Wind speeds are highest in the spring and are generally southwesterly. Canadian and Pacific cold fronts come through the region in fall, winter and spring with predictability and temperature changes can be rapid. Most of the precipitation comes in the form of rain and during the period from May through October. Snowfall averages around 15 inches but may be as little as 8 inches or as much as 36 inches. Rainfall in the growing season often comes as intense showers of relatively short duration. Long-term droughts occur on the average of once every 20 years and may last as long as five to six years (during these drought years moisture during the growing season is from 50 to 60 percent of the mean.) Based on long-term records, approximately 60 percent of years are below the mean rainfall and approximately 40 percent are above the mean. May, June and July are the main growth months for perennial warm-season grasses. Forbs make their growth somewhat earlier.

Table 3. Representative climatic features Frost-free period (average) 186 days Freeze-free period (average) 205 days Precipitation total (average) 21 in

Climate stations used (1) CAMERON [USC00291332], Grady, NM (2) PANHANDLE [USC00416785], Panhandle, TX (3) SILVERTON [USC00418323], Silverton, TX (4) BIG SPRING [USW00023041], Big Spring, TX (5) PORTALES [USC00297008], Portales, NM (6) DENVER CITY [USC00412408], Denver City, TX (7) CROSBYTON [USC00412121], Crosbyton, TX

Influencing water features None.

Soil features This site consists of very deep, well drained, moderately permeable soils that formed in loam and clay loam loess deposits. These are very well developed soils on old stable landforms and are moderately alkaline throughout. The soils have dark colored loam or clay loam surfaces and clay loam subsurface layers. Permeability is moderate, and available water holding capacity is moderate to high. The fertility of these soils is high and the root zone is easily penetrated by plant roots so the production capacity is high. These sites are subject to wind erosion if suitable cover is not present.

Major Soil Taxonomic Units correlated to this site include: Acuff loam, Estacado clay loam, Friona loam, Mansker clay loam, Olton clay loam, Pantex silty clay loam, Pullman clay loam, Tulia loam, and Zita loam.

Table 4. Representative soil features

Parent material (1) Eolian deposits–limestone Surface texture (1) Loam (2) Clay loam (3) Silty clay loam Family particle size (1) Loamy

Drainage class Moderately well drained to well drained

Permeability class Slow to moderate

Soil depth 20–80 in Surface fragment cover <=3" 0% Surface fragment cover >3" 0%

Available water capacity 6–12 in (0-40in)

Calcium carbonate equivalent 0–20% (0-40in)

Electrical conductivity 0–2 mmhos/cm (0-40in)

Sodium adsorption ratio 0–2 (0-40in)

Soil reaction (1:1 water) 6.6–8.4 (0-40in)

Subsurface fragment volume <=3" 0–2% (Depth not specified) Subsurface fragment volume >3" 0% (Depth not specified)

Ecological dynamics The reference plant community for this site is a Shortgrass/Blue grama Dominant Community (1.1). A few midgrasses can be found in small depressions along with a small number of moisture dependent forbs. Very little woody are found. A few cholla ( imbricata), prickly pear (Opuntia spp.), or occasional yucca (Yucca spp.) will be present, usually only 1 to 2% of the total plant community. Blue grama (Bouteloua gracilis) dominates with a lesser amount of buffalograss ( Bouteloua dactyloides) present. Western wheatgrass (Pascopyrum smithii) and vine mesquite (Panicum obtusum) may occur in low places that catch and hold more moisture. The major perennial forbs are scarlet globemallow (Sphaeralcea coccinea), chocolate daisy (Berlandiera lyrata), slimleaf scurfpea (Pediomelum linearifolium), prairie coneflower (Ratibida columnifera), and baby white aster (Chaetopappa ericoides). Annual forbs are more abundant in years of above average spring rainfall. As a rule, forbs contribute around 5 to 8 % of the total production. This site is not highly diverse as the clayey soils along with relatively low rainfall limit the range of species adapted to the site. Drought tolerant species prevail. Bison historically grazed the site and the plants are palatable to cattle. The highly palatable forage and level terrain make this a choice grazing site even though production is only moderate. prefer this site, especially in spring when forbs are more abundant.

Fire plays a major role in maintaining the reference community. In general, woody plants are suppressed and grasses are perpetuated. Fire also influences grazing patterns. Animals are attracted to the regrowth of herbage in burned areas. Forbs become more profuse for a time following fire and attracted animals such as pronghorns that prefer forbs to grass. Fire in combination with a favorable growing season will generally tend to sustain the perennial shortgrass community. In contrast, fire in combination with drought can be a transitional pathway that can result in some plant community changes. Grasses that thrive on disturbance include sand dropseed (Sporobolus cryptandrus) and silver bluestem (Bothriochloa laguroides). Perennial forbs and shrubs may increase for a period of time. Fire can cause adverse effects to the perennial grass community under high fuel loads and summer heat conditions. Generally, this site does not produce the amounts of fine fuel needed to generate the amount of heat needed to kill woody vegetation. An exception to this may be plains prickly pear. The good palatability of the forage on this site makes it unnecessary to consider burning for improving forage quality. Prescribed fire is not often applicable as a management tool.

The reference community for this site also developed under a grazing ecology. Large herbivores grazed the grasslands and moved on seeking fresh forage. On the high plains plateau, the frequency of grazing was greatly influenced by availability of water. There are historical accounts of Spanish conquistadors encountering buffalo as the parties crossed the plains. Large amounts of water were needed to support the huge bison herds. During dry times the herds most likely grazed the edge of the plains near the breaks leading to the creeks and rivers. When grazing did occur it was probably severe. Recovery periods were likely long with the animals not returning to the same spot for a year or even more.

This is a preferred site for domestic livestock and overgrazing can easily occur. When continued overgrazing occurs over a long period of time, blue grama will develop a low vigor, stunted appearance. This is a response to constant grazing pressure. With continued heavy grazing pressure brings about a new plant community, the Degraded Shortgrass Community (1.2). The soil becomes more compacted, rainfall infiltration is reduced, and water runoff increases. Western wheatgrass, the only cool-season grass present, decreases under grazing pressure. Long-term abuse coupled with drought will often leave the turf open in places. Increasing species such as broom snakeweed (Gutierrezia sarothrae) can gain a foothold. Careful grazing management and control of invading/increaser competition can restore this site to the reference condition.

If long-term heavy grazing continues, a threshold will be crossed to a Broom snakeweed/Annual Forb Dominant Community (2.1). In this degraded state, blue grama loses its bunchgrass characteristics and assumes a sod bound appearance because of grazing pressure. The shortgrass species are so resistant to grazing that it is uncommon for them to be killed out, but they can be weakened dramatically. Weedy and/or halfshrub species such as broom snakeweed may increase and dominate this site along with perennial threeawn (Aristida purpurea) and annuals. In the eastern portions of MLRA 77C, mesquite (Prosopis glandulosa) is a common invader. In the western portions of MLRA 77C, cholla (Opuntia imbricata) and other cacti species may invade and possibly dominate the site. Nutrient cycling, the water cycle, watershed protection and biological functions have been severely reduced. The plant community is so degraded that it cannot reverse retrogression without extensive energy and management inputs. Restoration of the Shrub/Forb State (2.1) to the Grassland State will require prescribed grazing with rest periods during the growing season. Re-seeding bare areas with adapted native species, and chemical and/or mechanical brush management and some form of pest management will be necessary. Prescribed grazing along with the control of invading competition will usually restore this site within a few years provided judicious grazing management is applied. This site is perhaps one of the most resilient sites in MLRA 77C.

NOTE: Rangeland Health Reference Worksheets have been posted for this site on the NRCS website (www.tx.nrcs.usda.gov) in Section II of the eFOTG under (F) Ecological Site Descriptions.

STATE AND TRANSITIONAL PATHWAYS: (DIAGRAM)

Narrative: The following diagram suggests some pathways that the vegetation on this site might take. There may be other states not shown on the diagram. This information is intended to show what might happen in a given set of circumstances; it does not mean that this would happen the same way in every instance. Local professional guidance should always be sought before pursuing a treatment scenario.

As a site changes in the structure and makeup of the plant community, the changes may be due to management or due to natural occurrences or both. At some point in time thresholds are crossed. This means that once changes have progressed to some certain point, the balance of the community has been altered to the extent that a return to the former state is not possible, that is, not possible unless some form of energy is applied to make it happen. These changes take place on all ecological sites, but some sites support communities that are more resistant to change than other sites. Also, some sites are more resilient, that is, they tend to be able to heal or restore themselves more easily. Usually, changes in management practices alone, such as grazing techniques, will not be sufficient to restore former plant communities. An example of energy input might be the implementation of chemical or mechanical brush management to decrease the amount of woody shrubs and increase the amount of grasses and forbs. This shift in community balance could not be brought about with grazing alone. The amount of energy required to bring about a change in plant community balance may vary a great deal depending on the present state and upon the desired result.

State and transition model Figure 6. R077CY022TX

State 1 Grassland State The reference plant community for this site is a Shortgrass/Blue grama Dominant Community (1.1). A few midgrasses can be found in small depressions along with a small number of moisture dependent forbs. Very little woody plants are found. A few cholla cactus, prickly pear, or occasional yucca will be present, usually only 1 to 2% of the total plant community. Blue grama dominates with a lesser amount of buffalograss present. Western wheatgrass and vine mesquite may occur in low places that catch and hold more moisture. The major perennial forbs are scarlet globemallow, chocolate daisy, slimleaf scurfpea, prairie coneflower, and baby white aster. Annual forbs are more abundant in years of above average spring rainfall. As a rule, forbs contribute around 5 to 8 % of the total production. This site is not highly diverse as the clayey soils along with relatively low rainfall limit the range of species adapted to the site.

With continued heavy grazing pressure brings about a new plant community, the Degraded Shortgrass Community (1.2). The soil becomes more compacted, rainfall infiltration is reduced, and water runoff increases. Western wheatgrass, the only cool-season grass present, decreases under grazing pressure. Long-term abuse coupled with drought will often leave the turf open in places. Increasing species such as broom snakeweed can gain a foothold.

Community 1.1 Shortgrass/Blue grama Dominant Community

Figure 7. 1. 1 Shortgrass/Blue grama Dominant Community

The interpretive or "reference" plant community for this site is a shortgrass dominated community with blue grama being the dominant grass with lesser amounts of buffalograss (average of 60 – 70 percent blue grama and 15 – 25 percent buffalograss). There are a few other species of shortgrasses present making up from 5 to 10 percent of total production. Western wheatgrass and vine mesquite are often present in depressions and on slopes above playa lakes. There are approximately 5 percent forbs and almost no woody shrubs or trees present.

Table 5. Annual production by plant type

Low Representative Value High Plant Type (Lb/Acre) (Lb/Acre) (Lb/Acre) Grass/Grasslike 950 1475 2000 Forb 50 90 130 Shrub/Vine 40 50 60 Microbiotic Crusts 15 20 25 Tree 0 0 0 Total 1055 1635 2215

Figure 9. Plant community growth curve (percent production by month). TX1019, Shortgrass Dominant Community. Growth is predominately shortgrasses from April through October with a peak growth from May to July.. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 2 4 7 19 23 17 8 12 5 2 1

Community 1.2 Degraded Shortgrass Community

Figure 10. 1.2 Degraded Shortgrass Community

As retrogression occurs, the plant community is composed of low vigor blue grama and buffalograss with an increase in broom snakeweed and annual forbs. Blue grama and buffalograss will still dominate the site but total production will be reduced. Some Deep Hardland Sites in the western portion of MLRA 77C may see cholla and other cacti species increasing on the site, while sites in the eastern portion of MLRA 77C may see mesquite invasion to the point of domination. Nutrient cycling, the water cycle, watershed protection and biological functions have been reduced. The transition back to the reference community is possible with proper grazing management for several years. Chemical and/or mechanical brush management may be needed to reduce the increased canopy of invasive/increasing plants.

Table 6. Annual production by plant type

Low Representative Value High Plant Type (Lb/Acre) (Lb/Acre) (Lb/Acre) Grass/Grasslike 450 725 1000 Forb 100 180 260 Shrub/Vine 100 150 200 Microbiotic Crusts 5 10 20 Tree 0 0 0 Total 655 1065 1480

Figure 12. Plant community growth curve (percent production by month). TX1020, Shortgrass/BroomSnakeweed/Annual Forbs Community. Growth is predominately low vigor shortgrasses from April to October with peak growth from May to July. There are also encroaching shrubs and annual forbs..

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 1 3 5 20 25 17 8 15 4 1 1

Pathway 1.1A Community 1.1 to 1.2 Shortgrass/Blue grama Degraded Shortgrass Dominant Community Community

With heavy continuous grazing and brush invasion of broom snakeweed, cholla, and pricklypear, the Shortgrass/Blue grama Dominant Community shifts to the Degraded Shortgrass Community.

Pathway 1.2A Community 1.2 to 1.1

Degraded Shortgrass Shortgrass/Blue grama Community Dominant Community

With the implementation of various conservation practices such as Prescribed Grazing, the Degraded Shortgrass Community can revert back to the Shortgrass/Blue grama Dominant Community.

Conservation practices Prescribed Grazing

State 2 Shrub/Forb State If long-term heavy grazing continues, a threshold will be crossed from a Grassland State (1) to a Shrub/Forb State (2). In this degraded state, blue grama loses its bunchgrass characteristics and assumes a sod bound appearance. The shortgrass species are so resistant to grazing that it is uncommon for them to be killed out, but they can be weakened dramatically. Weedy and/or halfshrub species such as broom snakeweed may increase and dominate this site along with perennial three-awn and annuals. In the eastern portions of MLRA 77C, mesquite is a common invader. In the western portions of MLRA 77C, cholla and other cacti species may invade and possibly dominate the site.

Community 2.1 Broom Snakeweed/Annual Forbs Dominant Community

Figure 13. 2.1 Broom Snakeweed/Annual Forb Dominant Communit Figure 14. 2.1 Cholla

Figure 15. 2.1 Mesquite

In this phase of retrogression a threshold has been crossed. Broom snakeweed and annuals dominate the site with large and numerous amounts of bare ground scattered throughout the site. Blue grama and buffalograss are in low vigor and the blue grama has lost its bunchgrass characteristics and has now assumed a sod bound appearance. Three-awns are encroaching the site. Some Deep Hardland sites in the eastern and far southwestern portion of MLRA 77C may see mesquite dominating the site. Some Deep Hardland sites in the western portion of MLRA 77C may see cholla and other cacti species dominating. Production of grass is low, and the community integrity has been compromised. Ecological processes are not functioning as needed. Runoff is increased and infiltration is low. The plant community is so degraded that it cannot reverse retrogression without extensive energy and management inputs. Restoration back to the reference state will require prescribed grazing with rest periods during the growing season, re-seeding bare areas with adapted native grass species, and chemical and/or mechanical brush management along with some form of pest management.

Table 7. Annual production by plant type

Low Representative Value High Plant Type (Lb/Acre) (Lb/Acre) (Lb/Acre) Grass/Grasslike 300 400 500 Shrub/Vine 250 375 500 Forb 140 220 300 Microbiotic Crusts 20 35 50 Tree 0 0 0 Total 710 1030 1350

Figure 17. Plant community growth curve (percent production by month). TX1021, Broom Snakeweed/Annual Forb Dominant Community. Growth is predominately shrubs and forbs from April to October with a peak growth from April to June.. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 0 2 5 18 23 16 5 5 8 15 3 0

Transition T1A State 1 to 2 Due to heavy continuous grazing pressure and brush invasion of broom snakeweed, cholla, and pricklypear, the Grassland State will transition to the Shrub/Forb State.

Restoration pathway R2A State 2 to 1 With the application of several conservation practices such as Brush Management, Pest Management, and Prescribed Grazing, the Grassland State can be restored from the Shrub/Forb State.

Conservation practices Brush Management Prescribed Grazing Integrated Pest Management (IPM)

Additional community tables

Table 8. Community 1.1 plant community composition

Annual Production Foliar Cover Group Common Name Symbol Scientific Name (Lb/Acre) (%) Grass/Grasslike 1 Shortgrass/Midgrass 600–1400 blue grama BOGR2 Bouteloua gracilis 500–1000 – buffalograss BODA2 Bouteloua dactyloides 140–400 – sideoats grama BOCU Bouteloua curtipendula 60–120 – 2 Midgrasses 80–150 vine mesquite PAOB Panicum obtusum 50–100 – western wheatgrass PASM Pascopyrum smithii 50–100 – 3 Mid/Shortgrasses 40–80 Wright's threeawn ARPUW Aristida purpurea var. wrightii 20–50 – black grama BOER4 Bouteloua eriopoda 20–50 – silver beardgrass BOLAT Bothriochloa laguroides ssp. torreyana 20–50 – tumble windmill grass CHVE2 Chloris verticillata 20–50 – cottontop DICA8 Digitaria californica 20–50 – sand muhly MUAR2 Muhlenbergia arenicola 20–50 – James' galleta PLJA Pleuraphis jamesii 20–50 – tobosagrass PLMU3 Pleuraphis mutica 20–50 – sand dropseed SPCR Sporobolus cryptandrus 20–50 – 4 Shortgrasses 40–80 squirreltail ELELE Elymus elymoides ssp. elymoides 20–50 – gummy lovegrass ERCU Eragrostis curtipedicellata 20–50 – Forb 5 Forbs 50–130 5 Forbs 50–130 Forb, annual 2FA Forb, annual 0–50 – Cuman ragweed AMPS Ambrosia psilostachya 20–50 – sagebrush ARTEM Artemisia 20–50 – lyreleaf greeneyes BELY Berlandiera lyrata 20–50 – rose heath CHER2 Chaetopappa ericoides 20–50 – prairie clover DALEA Dalea 0–50 – Engelmann's daisy ENPE4 Engelmannia peristenia 20–50 – scarlet beeblossom GACO5 Gaura coccinea 20–50 – dotted blazing star LIPU Liatris punctata 20–50 – evening primrose OENOT Oenothera 20–50 – Fendler's penstemon PEFE Penstemon fendleri 20–50 – slimflower scurfpea PSTE5 Psoralidium tenuiflorum 20–50 – upright prairie RACO3 Ratibida columnifera 20–50 – coneflower scarlet globemallow SPCO Sphaeralcea coccinea 20–50 – white heath aster SYERE Symphyotrichum ericoides var. 0–50 – ericoides stemmy four-nerve TESC2 Tetraneuris scaposa 20–50 – daisy stiff greenthread THFI Thelesperma filifolium 20–50 – Shrub/Vine 6 Shrubs 40–60 tree cholla CYIMI Cylindropuntia imbricata var. imbricata 20–40 – broom snakeweed GUSA2 Gutierrezia sarothrae 20–40 – plains pricklypear OPPO Opuntia polyacantha 20–40 – yucca YUCCA Yucca 20–40 –

Animal community Native animals that occupy this site include , antelope, coyote, jackrabbit, swift fox, Texas horned lizard, prairie dogs and various small mammals and grassland birds. It is an open grassland site; therefore, species that require cover will not be resident. For specific guidance on wildlife, Wildlife Habitat Appraisal Guides are available through NRCS for several species. Prairie dogs were a part of the natural ecosystem and their towns were extensive in the plains. Before settlement, prairie dogs were able to expand into new territory at will. There were also more natural predators present, such as the black-footed ferret. The towns could spread out and the burrows were likely well spaced. Today prairie dogs often occupy a relatively small tract of range and over populate through lack of space and predators. Sever abuse of the plant community occurs. Once severe abuse by prairie dogs takes place, the site may never regain the structure and composition of the reference state.

Plant preference by animal kind:

This rating system provides general guidance as to animal preference for plant species. It also indicates possible competition between kinds of herbivores for various plants. Grazing preference changes from time to time, especially between seasons, and between animal kinds and classes. Grazing preference does not necessarily reflect the ecological status of the plant within the plant community. For wildlife, plant preference for food and cover are rated.

Preferred (P) – Percentage of plant in animal diet is greater than it occurs on the land Desirable (D) – Percentage of plant in animal diet is similar to the percentage composition on the land Undesirable (U) – Percentage of plant in animal diet is less than it occurs on the land Not Consumed (N) – Plant would not be eaten under normal conditions. It is only consumed when other forages not available. Toxic (T) – Rare occurrence in diet and, if consumed in any tangible amounts results in death or severe illness in animal

Hydrological functions This site has very little slope, so runoff is slow. Runoff from the site often supplies nearby playa lakes, and this water eventually flows into the few major draws and streams in the area. With good vegetative cover, runoff contains low sediment. Infiltration is moderately slow and evaporation relatively high. If vegetative cover is poor, very little water gets into the soil.

Recreational uses This site is well suited for many recreational uses such as hunting, camping, hiking, bird watching, photography, and horseback riding.

Wood products None.

Other products None.

Other information None.

Inventory data references NRCS FOTG – Section II of the FOTG Range Site Descriptions and numerous historical accounts of vegetative conditions at the time of early settlement in the area were used in the development of this site description. Vegetative inventories were made at several site locations for support documentation.

Inventory Data References (documents): NRCS FOTG – Section II - Range Site Descriptions NRCS Clipping Data summaries over a 20 year period

Other references 1. Archer S. 1994. Woody plant encroachment into southwestern grasslands and savannas: rates, patterns and proximate causes. In Ecological implications of livestock herbivory in the West, Ed M Vavra, W Laycock, R Pieper, pp13-68, Denver, CO: society for Range Management 2. Gould F. 1978. Common Texas Grasses: an illustrated guide. College Station, TX: Texas A & M Press. 3. Hatch, Brown and Ghandi, Vascular Plants of Texas ( An Ecological Checklist) 4. Heischmidt RK, Stuth, Eds. 1991 Grazing Management: an ecological perspective. Portland OR: Timberline Press 5. Scifres CJ, Hamilton WT. 1993. Prescribed burning for brushland management: the South Texas example. College Station, TX: Texas A & M Press. 6. Natural Resources Conservation Service - Range Site Descriptions 7. USDA-Natural Resources Conservation Service - Soil Surveys & Website soil database

The following individuals assisted with the development of this site description: Clint Rollins –Rangeland Management Specialist- NRCS; Amarillo, Texas Justin Clary – Rangeland Management Specialist – NRCS; Temple, Texas Contributors Duckworth-Cole J.R. Bell Joe Norris

Acknowledgments Site Development and Testing Plan Future work, as described in a Project Plan, to validate the information in this Provisional Ecological Site Description is needed. This will include field activities to collect low, medium and high intensity sampling, soil correlations, and analysis of that data. Annual field reviews should be done by soil scientists and vegetation specialists. A final field review, peer review, quality control, and quality assurance reviews of the ESD will be needed to produce the final document. Annual reviews of the Project Plan are to be conducted by the Ecological Site Technical Team.

Rangeland health reference sheet Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.

Author(s)/participant(s) Stan Bradbury, Zone RMS, NRCS, Lubbock, Texas Contact for lead author 806-791-0581 Date 09/04/2007 Approved by Mark Moseley, RMS, NRCS, San Antonio, Texas Approval date Composition (Indicators 10 and 12) based on Annual Production

Indicators

1. Number and extent of rills: None to slight.

2. Presence of water flow patterns: None to slight.

3. Number and height of erosional pedestals or terracettes: None to slight.

4. Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground): 0-10%, small pockets of non-connected areas.

5. Number of gullies and erosion associated with gullies: None to slight.

6. Extent of wind scoured, blowouts and/or depositional areas: None to slight. 7. Amount of litter movement (describe size and distance expected to travel): None to slight.

8. Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values): Very resistant to erosion.

9. Soil surface structure and SOM content (include type of structure and A-horizon color and thickness): Soil surface 0 to 9 inches thick; brown loam to clay loam; moderate medium and fine granular structure; slightly hard; friable; many roots; non-calcareous; neutral pH.

10. Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff: High canopy basal cover and density with small interspaces should make rainfall impact minimal. This site has moderately permeable soils, runoff is slow to moderate, available water holding capacity is high and wind erosion is low to moderate.

11. Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site): None.

12. Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):

Dominant: Warm-season shortgrasses >>

Sub-dominant:

Other: Warm-season midgrasses > cool-season grasses = forbs > shrubs/vines

Additional:

13. Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence): Grasses due to their growth habit will exhibit some mortality and decadence, though minimal.

14. Average percent litter cover (%) and depth ( in): Litter is dominantly herbaceous.

15. Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual- production): 1,300 to 1,700 pounds per acre.

16. Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site: Pricklypear, yucca and cholla. Broom snakeweed can become invasive.

17. Perennial plant reproductive capability: All plant species should be capable of reproduction except during periods of prolonged drought conditions, heavy natural herbivory or intense wildfires.